[Prognostic value of stress echocardiography by dobutamine combined with atropine]

PURPOSE

To determine the prognostic value of dobutamine-atropine stress echocardiography (DASE).

METHODS

We studied 452 consecutive patients at high risk for coronary artery disease, using DASE. They were followed during a mean period of 23 months.

RESULTS

There were 9 cardiac deaths and 2 acute myocardial infarctions in the group of patients with positive tests, and there were 2 myocardial infarctions and 1 cardiac death in patients with negative DASE.

CONCLUSION

We conclude that DASE reliably identifies patients at high risk for hard cardiac events.

[Prognostic value of stress echocardiography by dobutamine combined with atropine]

PURPOSE

To determine the prognostic value of dobutamine-atropine stress echocardiography (DASE).

METHODS

We studied 452 consecutive patients at high risk for coronary artery disease, using DASE. They were followed during a mean period of 23 months.

RESULTS

There were 9 cardiac deaths and 2 acute myocardial infarctions in the group of patients with positive tests, and there were 2 myocardial infarctions and 1 cardiac death in patients with negative DASE.

CONCLUSION

We conclude that DASE reliably identifies patients at high risk for hard cardiac events.

Effects of antianginal therapy with a calcium antagonist and nitrates on dobutamine-atropine stress echocardiography. Comparison with exercise electrocardiography

BACKGROUND

Anti-ischaemic therapy with nitrates and/or calcium channel blockers profoundly affects the results of pharmacological stress echocardiography with coronary vasodilators but the influence on catecholamine stress testing remains unsettled.

AIMS

The present study aimed to assess the effects of non-beta-blocker antianginal therapy on dobutamine (up to 40 micrograms.kg-1.min-1)-atropine (up to 1 mg) stress. echo-cardiography and to evaluate whether drug-induced changes in the dobutamine atropine stress echocardiography response may predict variations in exercise tolerance.

METHODS

Twenty six patients with angiographically assessed coronary artery disease (seven patients with single-, 10 with double-, and nine with triple-vessel disease) performed a dobutamine atropine stress echocardiography and an exercise electrocardiography test in random order both off and on antianginal drugs (nitrates and calcium antagonists). In doubtamine-atropine stress echocardiography, we evaluated: dobutamine time (i.e. the time from initiation of the dobutamine infusion to obvious dyssynergy), wall motion score index (in a 16-segment model of the left ventricle, each segment ranging from 1 = normal, to 4 = dyskinetic), and rate-pressure product at peak stress.

RESULTS

Dobutamine-atropine stress echocardiography positivity occurred in 26 out of 26 patients off and in 23 patients on therapy (100 vs 88%, P = ns). Atropine coadministration was needed to evoke echo positivity in no patient off and in five out of 26 on therapy (0 vs 19% P < 0.01). The achieved rate pressure product during dobutamine-atropine stress echocardiography was comparable on and off therapy (17 +/- 4 vs 19 +/- 5 x 10(3) mmHg x heart rate. min-1, P = ns). Therapy induced an increase in dobutamine time (on = 16 +/- 3 vs of = 13 +/- 3 min, P < 0.01) and a decrease in peak wall motion score index (on = 1.3 +/- 0.2 vs off = 1.5 +/- 0.3, P < 0.01). The therapy induced changes in exercise time during the exercise electrocardiography test were not significantly correlated to dobutamine-atropine stress echocardiography variations in either dobutamine time (r = 0.07, P = ns), or peak rate pressure product (r = 0.24, P = ns), or peak wall motion score index (r = 0.02, P = ns).

CONCLUSIONS

(1) non-beta-blocker antianginal therapy only modestly reduces dobutamine-atropine stress echocardiography sensitivity, although atropine coadministration is more often required to reach stress echo positivity under therapy; (2) therapy reduces the severity of dobutamine atropine stress echocardiography ischaemia stratified in the time and space domain, but these changes are only poorly correlated to variations in exercise tolerance.

Heterogeneity of left ventricular regional wall thickening following dobutamine infusion in normal human subjects

BACKGROUND

Pathophysiological data and pragmatic clinical experience with stress echocardiography suggest that inotropic stimulation with simultaneous changes in heart rate and loading conditions can affect the function of various myocardial regions asymmetrically, inducing heterogeneity in wall motion and thickening, possibly mimicking 'ischaemic' regional hypokinesis or lack of hyperkinesis during stress.

OBJECTIVES

To describe, in a quantitative fashion, the physiological contractile response of different left ventricular regions following dobutamine infusion.

METHODS

Two hundred and twenty-three in-hospital patients undergoing dobutamine stress echocardiography and coronary angiography were initially considered. Of these 223 patients, 18 had angiographically normal coronary arteries, normal resting function, negative ergonovine and exercise stress tests, and negative dobutamine stress echocardiograms; of the 18, only in 11 patients (six females, age = 56 +/- 10 years) was it possible to obtain quantitative measurements of the middle segments of the inferior, anterior, lateral, and septal walls. Two-dimensional echocardiographic measurements of wall thickness were obtained at the end-diastolic (onset of Q wave) and end-systolic phases, both at baseline (rest) and at the peak of the dobutamine infusion (40 micrograms.min-1.kg-1 plus atropine).

RESULTS

Dobutamine increased heart rate (rest = 69 +/- 9 vs dobutamine = 138 +/- 13 beats.min-1; P < 0.01), whereas systolic blood pressure did not change significantly (rest = 136 +/- 15 vs dobutamine = 150 +/- 25 mmHg, P = ns). During stress, % systolic thickening decreased in the inferior wall (rest = 73 +/- 24 vs dobutamine +/- 50 +/- 9%; P < 0.01), whereas it tended to increase to a variable extent in the other regions, i.e. septal (rest = 46 +/- 17 vs dobutamine = 68 +/- 13%, P < 0.01), anterior (rest 62 +/- 19 vs dobutamine = 69 +/- 11%, P = ns), and lateral wall (rest = 48 +/- 16 vs dobutamine = 61 +/- 18%, P = ns). The decrease in % systolic thickening of the inferior wall was inversely correlated with the increase in end-diastolic wall thickness (r = -0.75; P < 0.01), but neither with heart rate (r = 0.15; P = ns) nor with systolic blood pressure changes (r = 0.05; P = ns).

CONCLUSIONS

Heterogeneity of left ventricular wall thickening can be induced or magnified by dobutamine infusion even in subjects without coronary artery disease, with the inferior wall showing a lack of hyperkinesis, up to relative hypokinesis, in comparison with other myocardial regions. Caution in aggressive dobutamine stress echocardiography reading, especially in the inferior wall, might be warranted.